Onslow Iowa ZIP Codes

Onslow holds a single ZIP code.

Every ZIP code in Onslow

The complete list of Onslow, Iowa ZIP codes with the county each falls in.
ZIP code	County
52321	Jones County

We do not publish a delivery type (standard, PO box, unique) or a neighbourhood for each ZIP. USPS delivery-type products are licensed, and no clean-rights source maps ZIP codes to neighbourhoods — so the Onslow codes above are listed without a column we would have to invent.

Scope every ZIP code recorded for Onslow. Source GeoNames US postal codes (2026-07 postal dump) and Census 2024 county Gazetteer (2024 Gazetteer). Updated 15 July 2026. ZIP codes are delivery-route groupings, not areas; the boundaries implied by any ZIP map are approximations.

How these codes cluster

Every Onslow ZIP code begins 523. Those first three digits identify the sectional center facility that processes mail for this part of Iowa. Statewide that range covers 53 ZIP codes, so Onslow accounts for 2% of it.

Every Iowa ZIP prefix and the region it covers →

Area codes covering Onslow

ZIP codes and area codes are separate systems — one routes mail, the other routes calls — and they do not share boundaries. The code below serves the same ground Onslow occupies.

563 Area code 563

Onslow Iowa area codes in full →

Where Onslow's ZIP codes sit

Each point is one Onslow ZIP code, plotted from its record coordinates.

Reference points and footprint
Not an official NANPA boundary
Not a USPS delivery area

Cities near Onslow

The closest places to Onslow with their own ZIP code list, nearest first.
City	Distance	ZIP codes
Wyoming Iowa ZIP codes	3.3 mi	1 ZIP code
Monmouth Iowa ZIP codes	7.2 mi	1 ZIP code
Oxford Junction Iowa ZIP codes	9.1 mi	1 ZIP code
Baldwin Iowa ZIP codes	9.3 mi	1 ZIP code
Olin Iowa ZIP codes	10 mi	1 ZIP code
Monticello Iowa ZIP codes	12 mi	1 ZIP code
Anamosa Iowa ZIP codes	13 mi	1 ZIP code
Cascade Iowa ZIP codes	14 mi	1 ZIP code

Straight-line distance between place reference points, not driving distance.